Russlk said:
If you parallel the two channels, it is still 50W, but if you invert one channel and drive both ends of the speaker, it is 4 times (E^2/R), 200W.
A familiar misleading bridged amplifier statement!.
Power is all about available voltage levels and the impedance of the speaker - two amplifiers bridged provide TWICE the voltage capability, and would (in theory) provide FOUR times the power.
However, this requires that the amplifiers are able to provide the required power into that impeadance (each half of the bridged amplifier effectively feeds HALF of the speaker impedance).
Basically bridging provides exactly the same amount of power, BUT into a different impedance.
So, assuming your amplifier module can each provide 50W into 4 ohms, you have three options:
1) 2x50W into two seperate 4 ohm speakers (total 100W stereo).
2) Amps in parallel - 1x100W into one 2 ohm speaker (or the same two 4 ohm speakers in parallel) - assuming the amps are happy working in parallel! (total 100W mono).
3) Bridged amps - 1x100W into one 8 ohm speaker (or the same two 4 ohm speakers in series) - (total 100W mono).
As a 'possible' fourth option, as suggested in the previous post:
4) Bridged amps - 1 x 200W into one 4 ohm speaker, each amp is trying to provide 100W into 2 ohms, both amps overheat and are destroyed!.
Notice all the working options (1, 2 and 3) give exactly the same power (100W) into exactly the same two 4 ohm speakers), but option 1) is stereo, the others only mono. Where bridging comes in is where you don't have two 4 ohm speakers, but only one 8 ohm speaker - in which case you can still get full power, but only in mono.